This invention relates to calibration of electrical measuring instruments.
Over time, and under changing ambient conditions, the operation of a measuring instrument may vary so the value of a given electrical parameter returned by the instrument may shift. Typically the instrument is calibrated regularly to compensate for these shifts. During calibration, the instrument is presented with a precision electrical parameter whose value is known accurately. The offset between the known value and the value measured by the instrument is then used to adjust subsequent instrument readings.
Normally, instruments are returned to the manufacturer or other service facility to perform the calibration.